Surface-contact railway system.



W.'B. POTTER. SURFACE CONTACT. RAILWAY SYSTEM.

PATENTED' MAY 26, 1903.

APPLICATION FILED FEB. 11, 1899;

NOMODEL.

Witnesses: Inventor:

I Wi I am BJ O'UDQT,

THE NORRI$ PEYERS CO PHOTO-LUNG WASHINGTON, Dv l2,

UNITED STATES P TENT Patented May 2c, 1903.

OFFICE.

WILLIAM B. POTTER, OF SOHENEOTADY, NEW YORK, ASSIGNOR TO THE GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

SU RFACE-QONTACT RAILWAY SYSTEM.

SPECIFICATION forming part of Letters Patent No. 729,411, dated May 26,1903.

I Application filed February 11, 1899. Serial No. 705,235. (No model.)

fect which may occur with many systems at present in use in which theso-called leakage-current may act to hold up one or more of theelectromagnetic switches. In general these systems comprise a feeder,sectional conductors or contacts which may be contact studs or rails ofconsiderable length, and electromagnetic switches of one form or anotherwhich are operated by certain circuits to connect the sectionalconductors in sequence to the feeder as the car passes and to disconnecteach conductor-section as soon as the collector is carried by the car tomake contact with the next succeeding section. Usually two rows of studsor sectional conductors are employed, one of Which,'commonly called theworking conductor, is connected to the feeder, and the other of which,called the energizing-conductor, is connected to the coils of theelectromagnetic switches,thecoilsbeingusuallygrounded. It is manifestthat with this arrangement if there should be for any reason-as, forinstance, by

.wet weather or by accidental connection being made between themaleakage of current from the working conductor which has been connectedto-the feeder to the corresponding energizing-conductor operating itsswitch the latter would be held up and the 7 working conductor would bemaintained alive in the street. This has been a source of danger in somesurface-contact systems, and several attempts have been made to overcomeit, most of which are not altogether successful. I am aware ofcertainpatents which disclose methods of short-circuiting the line,andthereby blowing a fuse at a leaking section, or of shunting theline-current at a leaking section to operate an auxiliary feeder-switch.These I aim by the present invention to eliminate this difficulty, whichI do by providing upon the car a means of shunting to ground anyleakage-current which might otherwise pass from the Working conductor tothe energizing-conductor. The means employed are such as to operateafter the collector or contact-shoe which collects the motor-current(and which usually operates the pick-up switches) has left the workingconductor.

Briefly described, one construction of apparatus embodying the inventionis as follows: In addition to the ordinary motor-shoe or workingcollector, which also operates the pick-up switches, I provide othershoes,which are grounded, and so arrange these latter that they willmake contact with all of the sections of energizing-conductorswithout'touching any of the working conductors. As a convenient methodof effecting this result I extend the sections of energizing-conductorsso that the grounded auxiliary shoes may be out of line with themotor-shoe and still register with the energizing-conductor.

In the drawing attached to this specification, which represents indiagram one form which my invention may take, A is a generator, one poleof which is connected to the track-rail or ground D, while the otherpole is connectedto a feeder H. Located along the line of the road is asectional conductor B, which may be of any preferred form, but is hereshown as composed of a succession of studs supposed to project only ashort distance above the surface of the earth. Each of these studs isconnected to two magnetically-operated switches G, as shown, so that theclosing of either switch will connect the stud with the feeder H. A shoeF travels upon the studs B and collects current for the motor or motorsM. For example, in the position shown current flows from the feeder IIto the switch G, to the working collector F, to the motor M, through theca'rwheel I, to ground at D, and thence backto the generator A. I do notillustrate thecontrol-lers,&c., as they are now well known in the artand form no part of my present invention.

The switches G are actuated by coils P, each of which is connected atone end to ground, as shown, or to the track-return and and the switchwill open.

at the other end to one of the studs 0, In the position shown currentflows from the shoe F to the stud 0, through the coil P, and to ground.The coils P are so proportioned that the current is small in amount ascompared with the current normally flowing t0 the motors.

The system as thus far explained will operate when once the switch G isclosed, as the shoe F will always as the car moves in either directionfurnish current for picking up each switch G, controlling the stud Bnext in advance. Normally each switch G will open when the shoe F leavesthe corresponding stud C; but it may happen, as has been stated above,that current will leak from the live stud B to the stud C after the shoeF has passed over them, and thus the switch G might be held closed. Toavoid this, I so shape each of the studs 0 that it makes contact notonly with the shoe F, but also with the auxiliary shoes F F, which areconnected direct to ground through the car-axle, as shown. Suppose thatin the illustration the car is moving to the right. The shoe F isfurnishing current to the car-motors from the working stud B and formswith the energizing-stud C a shunt to ground through the switch-coil P.The shoe F has just left the next rear energizing-stud with which thegrounded shoe F is about to engage. When this engagement takes place,any leakagecurrents, even those which may be passing from the workingstud through the coil of the switch which is connected to the next rearenergizing-stud, will be shunted by the shoe F through the car-axle tothe track-return The shoe F continues thus to short-circuittheswitch-coil to earth until the shoe F has been carried beyond theenergizing-stud O and has left the switch G open and the working stud Bdeenergized. However, if leakage currents should keep the switch Gclosed the working stud B would remain alive and leakagecurrents mightflow therefrom after the shoe F had left the next rear energizing-studand pass through the switch-coil to close the switch and leave the rearenergizing-stud alive. To prevent this occurrence, the shoe F is ofsufficient length to bridge the two successive energizing-studs betweenwhich the stud B is located, and thus the leakagecurrents are shuntedfrom the stud O to ground, and it is impossible for the stud B to remainenergized after the shoe F has cleared the energizing-stud behind B.

In order to insure the above-described operation when the car is movingin either direction, the energizing-studs C C, &c., extend or are offsetlaterally in both directions from the line of the working studs B B, &c.

For the purpose of picking up the switches when the car has lost itscurrent I may provide a storage battery SB, carried on the car. One endof this battery is connected to ground and one end to the shoe F througha switch S.

It will be evident that by merely closing this switch for an instant itwill be possible to pick up the switch G and start the system inoperation. To avoid the necessity of carrying a storage battery on eachcar, I may provide contacts L, located, for example, in lamp-posts L atnumerous points along, the track or on another car. One or more contactsK K on each car will be connected to the shoe F either with or withoutthe interposition of the switch S. It now the contacts L and K beconnected together, as by the flexible conductor N, current suificientto pick up the switch G will be at once available.

So far as I am aware I am the first in the art to provide means carriedupon the car for preventing the electromagnetic switches of asurface'contact railway system from being held up by leakage-currentwithout rendering any portion of the system inoperative or without theprovision of extra apparatus and the first to carry an independentshunt-circuit for leakage-currents alone upon a car in such a system.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent of the United States, is

1. In a surface-contact system, the combination of a source of current,sectional conductors, and electromagnetic switches for connecting theconductors in sequence to the source of current as a vehicle passes overthe road, with means carried by the car for shunting leakage-currentsfrom the sectional conductors directly through the car to ground.

2. In a surface-contact system, the combination of a feeder, sectionalconductors, and electromagnetic switches for connecting anddisconnecting the feeder and the conductors in sequence, with a shortcircuit direct to ground for leakage-currents,carried upon the car.

3. The combination in a surface-contact system, with a feeder, buttonsconnected to the feeder, an electromagnetic switch the coils of whichare connected to pick-up buttons or studs in the roadway and which areoperated in sequence to connect the firstnamed buttons with the feeder,of a circuit direct to ground carried upon the car and touching thepick-up buttons or studs only.

4. The combination with a feeder, studs connected to the feeder insequence by electromagnetic switches the coils of which are in circuitwith pick-up studs, of a shoe carried by the car and connected direct toground, the shoe registering with the pick-up studs only.

5. In a surface-contact system, the combination of two rows of studs, afeeder, and electromagnetic switches, one of the rows of studs beingconnected directly to the feeder by the action of the switches, and theother row of studs being grounded through pick-up coils, the latter rowof studs being of greater width than the former so as to project beyondthem upon either side of a central line,

with a shoe making contact with both rows of studs supplying current tothe motor and actuating the switches as it touches the studs insequence, and grounded shoes in front and rear of the first, but out ofline with it, so as to touch only one set of studs, whereby the car actsto short-circuit to ground any leakage reaching the pick-upstuds and toprevent the switches being held up by leakage-currents.

6. In an electric-railway system, the combination with the feeder, of asectional working conductor normally disconnected therefrom, anelectromagnetic switch between each conductonsection and the feeder, asectional switch-energizing conductor independent of said workingconductor, and means for shunting leakage-currents from theenergizing-condoctors to ground.

7. In an electric-railway system, the combination with the feeder, of asectional working conductor normally disconnected therefrom, anelectromagnetic switch between each conductor-section and the feeder, asectional switch-energizing conductor independent of said workingconductor, a car, and means for shunting leakage-currents from theenergizing-conductor through the car to ground.

8. In an electric-railway system, the combination with the feeder, of asectional working conductor, an electromagnetics witch between eachconductor-section and the feeder, a sectional switch-energizingconductor independent of said working conductor, a car, a workingcollector carried by the car which engages with the energizing-conductorsecv tions and collects working current from the Working conductor, andmeans for simultaneously therewith shunting leakage-currents to groundfrom the energizing-conductor section which the working collector hasjust left.

9. In an electric-railway system, the combination with the feeder, ofasectional working conductor, an electromagnetic switch between eachconductor-section and the feeder and having its coil connected toground, a sec tional switch-energizing conductor, each section of whichis connected with the coil of one of said switches, and meansfor-shunting leakage-currents from the energizing-conductor to ground.

10. In an electric-railway system, the combination witlrthe feeder, of asectional working conductor, an electromagnetic switch between eachsection and the feeder, a sectional switch-energizing conductor, anelectric-motor car, a collector carried by the car, connected with themotors, and engaging with the working and energizing conductors, and agrounded collector carried by the car which engages only with theenergizing-conductor.

11. In an electric-railway system, the combination with a sectionalworking conductor, of a sectional energizing-conductor, aworkingcollector carried by the car, and an auxil iary collector carried by thecar, connected with the track, and engaging only with theenergizing-conductor. y

12. In an electric-railway system, the combination with the feeder, of asectional Working conductor, an electromagnetic switch between eachconductor-section and the feeder, a sectional energizing-conductor, eachsection of which is offset from the working conductor, a workingcollector carried by the car and engaging with both conductors; and agrounded collector carried by the car and engaging with the offsetportions of the energizing-conductor.

13. In an electric-railway system, the combination with the feeder, of asectional working conductor, an electromagnetic switch between eachconductor-section and the feeder, a sectional energizing-conductor, eachsection of which extends laterally in both directions from the line ofthe working conductor, a working collector carried by the car andengaging with both conductors, and a grounded collector carried by thecar and engaging with the lateral extensions of the energizingconductor. V

14:. In an electric-railway system, the combination with the feeder, ofa sectional working conductor, an electromagnetic switch between eachconductor-section and the feeder, a sectional switch -energizingconductor, a working collector carried by the car, and a groundedcollector carried by the car, of sufficient length to bridge twosuccessive sections of the energizing-conductor, wherebyleakage-currents are shunted to ground from the successive sections ofthe energizing-conductor.

15. In an electric-railway system, the combination with the feeder, of asectional working conductor, an electromagnetic switch between eachconductor-section and the feeder and having its coil connected toground, a sectional switch-energizing conductor, to each section ofwhich is connected the coil of one of said switches, a travelingcollector for shunting a portion of the working current from a sectionof the working conductor to a section of the energizing conductor andthrough the switch-coil to close the switch and energize the nextsection of working conductor, and an auxiliary traveling collector forshort-circuiting each switch-coil to ground v by shuntingleakage-currents from the corresponding section of energizing-conductor.

16. In an electric-railway system, the combination with the feeder, of asectional working conductor, two electromagnetic switches between eachcond uctor-section and the feeder and having their coils grounded, asectional energizing-conductor, each section of which is connected toone of the switch-coils, a traveling motor-current collector whichengages with both sectional conductors-and atra'veling groundedcollector which engages only with the energizing-conductor.

17. In an electric-railway system,'the com- ICC bination with thefeeder, of a sectional working conductor, 'electronmgnetie switchesbetween the conductor and the feeder, a sectional energizing-conductorindependent of said working eond uctor, means carried by the car forenergizing the switches and conducting current to the ear-lilotors, anda traveling" grounded collector which engages only with theenergizing-conductor to short-cirenit the coils of the switches toground.

1 In witness whereof I have hereunto set my hand this 9th day ofFebruary, 1890.

WILLIAM B. POTTER.

, \Vitnesses:

B. B. HULL, EDWARD WILLIAMS, J r.

